Combination telephone switch and dial



June 4, 1957 Y HEINE 2,794,861

COMBINATION TELEPHONE SWITCH AND DIAL Filed March 31, 1954 INVE/VI'OP z W 'Q/ ZMMM COMBINATION TELEPHQNE SWITCH AND DIAL Bruno Heine, Hamburg, Germany, assignor to Allgerneine Telet'on-Fahrik G. m. b. H., Hamburg, Germany Application March 31, 1954, Serial No. 429,172

Claims priority, application Germany January 19, 1954 3 Claims. (Cl. 17999) The present invention relates to improvements in switching arrangements, being especially adapted for use with a conventional telephone instrument with a selector dial to enable the setting of additional switching.

In selector dial type of telephone instruments now in use, full use of the space behind the selector disc has not been made with the result that where there are a large number of switching means, the housing of the telephone instrument has been made larger than necessary.

Thus, it is an object of the invention to make better use of the space behind the selector disc of a telephone instrument of the type described and hence substantially decrease the size of the housing thereof. This has been accomplished by using the selector dial for the direct setting up of the switching means which are mounted behind the selector dial.

While it has been proposed heretofore to use the selector dial for setting up sliding switch arms, the present invention overcomes certain disadvantages of prior proposals. For example, sliding switch arms have been avoided.

Another object of the invention is to provide a switching arrangement of the type described in which a push button is provided at the central axis of the finger plate for making contact with the selected contact of the switching device.

A further object is to provide a switching arrangement for selectively operating a plurality of switching devices, which is simple and reliable in operation and inexpensive to produce.

In general the disadvantages of prior devices have been overcome by the present invention in that the actual contact or spring set operation occurs only after a characterizing setting.

By the use of a single push button, according to the present invention, it is possible without the employment of complicated mechanical devices to provide as many as eleven additional contacts or spring sets to be operated independently of each other in a telephone instrument with a conventional selector guide. By adding a second push button, it is possible to greatly increase the number of different contacts that can be operated independently with a single selector dial.

A particularly simple arrangement is provided, according to the present invention, if the switch means initiating actual operation of the contacts or spring sets is arranged along the central axis of the selector dial.

One such embodiment of the invention is illustrated diagrammatically in Figs. 1 and 2. All parts not necessary for understanding the invention are omitted.

Fig. 1 shows a selector dial for operating eleven additional calling contacts in side View; Fig. 2 shows this selector dial in front elevation. The proper selector dial, which serves for giving digital pulses, consists of the finger-hole disc 1, the base plate 2, the pulse-producing elements 3 (not shown in detail) and the finger stop 4.

The central axis of the selector dial is provided with a Patent "ice central opening. The spindle 5 with the pressure knob 6 and spring 7 are located in the central opening. At the end of the spindle 5, a contact spring 8 with precious metal contacts is mounted by means of insulating material not shown. The insulating plate 9 disposed therebeneath carries a contact plate 10 with a precious metal coating as well as eleven contact elements 11 with precious metal coatings.

If the selector dial shown in Figs. 1 and 2 is used as a digital pulse-producer (e. g. for calling the exchange), the contact spring 8 is rotated on operating and releasing the selector dial but, contact with the insulating plate 9, the contact plate 10 or the contact elements 11 does not occur. Any additional friction, which could prevent normal running of the selector dial, is hence prevented.

If with the help of the selector dial one of the contact elements 11 is to be connected with the contact plate 10, the contact spring 8 is set up over the desired contact plate by means of the finger-hole disc 1. Whilst one finger has turned the finger-hole disc 1 up to the finger stop 4, the thumb for example can then operate the pressure knob 6 against the force of the spring 7. The contact spring 8 hence bridges the desired contact plate 11 with the contact plate 10. The contact, by which a circuit (e. g. call circuit), is closed can be operated as often as desired. After releasing the finger-hole disc 1, this is returned to its normal position by springy or resilient means not shown.

It is naturally also possible to replace the contact spring 8 by an operating member which is arranged to operate on spring sets mounted circularly at the positions of the contact plates 11. If these spring sets are provided with a suitable mechanical device, they can remain operated when the selector disc has been returned to the zero position.

What I claim is:

1. In a selective switch for an intercommunicating telephone system, the combination with a conventional tele phone selector dial assembly having a rotary finger selector disc of means mounted in said disc for movement in a plane perpendicular to the plane of rotary motion of the disc, said means including a spindle and means for moving said spindle in said perpendicular plane, a contact carrying element secured on said spindle beneath said disc for movement with said spindle, a base plate beneath said contact carrying element, said element being normally spaced from said base plate, and contact means on said base plate, said contact carrying element being movable to establish electrical contact with selected contact means upon said base plate by movement of said spindle in said perpendicular plane in the direction of said base plate.

2. The invention as claimed in claim 1, said contact carrying element being in the form of a spring blade extendig radially from said spindle, said blade carrying electrical contacts at its opposite ends, said base plate having a central contact part for engagement by the contact at one end of said blade and having also a circumferentially spaced series of contacts for selective engagement by the contact at the opposite end of said blade, said selective engagement being dependent upon rotation of said selector disc.

3. The invention as claimed in claim 1, said contact carrying element being mounted for joint rotary move ment with said selector disc and said spindle and being in the form of a spring blade extending radially from said spindle, said blade carrying an electrical contact at each end, said base plate having a central contact part for engagement by the contact at one end of said blade and having also a circumferentially spaced series of contacts for selective engagement by the contact at the opposite 4 0 end of said blade, said selective engagement being de- 1,992,389 Mpser Feb. 26, 1935 pendent upon rotation of said selector disc. 073,568 Shipton Mar. 9, 1937 2,370,264 Shann Feb. 27, 1945 References Cited in the file of this patent 2,622,154 Deschamps Dec. 16, 1952 UNITED STATES PATENTS 5 FOREIGN PATENTS 1,290,645 Nelson Jan. 7, 1919 297,454 Great Britain Sept. 12, 1929 1,894,828 Obergfell Jan; 17, 1933 823,685 France Oct. 18, 1937 

